Clamshell bucket



Allgo 22, 1944. E. H. LICHTENBER-G l 2,356,255

y CLAMSHELL BUKET v Filed June 19, 1943 2 Sheets-Sheet l EMV EMM/m Allg- 22, 194.4. E. H. LICHTENBERG 2,356,255

CLAMSHELL BUCKET Filed June 19, 1943 2 sheets-sheet 2 Patented Aug. 22, 1944 UNITED y STATES PATENT- I OFFICE cLAMsHELL BUCKET ,Eric H. Lichtenberg, Milwaukee, VWis., assigner` to The C. S. Johnson Company, Champaign, Ill., a corporation of Illinois l Y Application June 19, 1943,-seri'aiN0`. 491,436

The present invention pertains to improvements in clamshell buckets of the two-line type.

Generally stated, the object of the invention is to provide such a bucket in which provision is made for minimizing fouling, wear and breakage of the closing line.

Experience has shown that in such buckets failure of the closing line most frequently occurs due to kinking and fouling of this cable at its fair-lead on the bucket head. When the bucket is at rest, as, for example, on a pile of material, and the closing line is'slacked off, a kink frequently forms inthe latter at its fairlead. `Subsequent tensioning of the closing line, to close the jaws of the bucket and thus pick up a load, strains the line at the kink so that after continued use failure customarily occurs iirst at the point mentioned. The general object of the present invention is to overcome the difiiculty outlined through the provision in the bucket of .a swivel type fair-lead, coordinated in a novel manner with the other4 elements of the i structure in such a way as to prevent kinking or fouling of the closing line.

In a more specific sense, the invention also resides in the provision of such a bucket with a swiveled fair-lead for the closing line and a coordinated novel guard arrangement for protecting the fair-lead mechanism when the bucket falls over on its side, as is frequently the case in ordinary use.

Further objects and advantages of the invention will become apparent as the following description proceeds, taken in connection withl the accompanying drawings in which:

Figure l is a side elevation of a clamshell bucket embodying the present invention, the bucket being shown in closed position and the guard about the swiveled fair-lead being vertically se'ctioned to expose the interior arrangement of -the parts.

Fig. 2 is an end elevation of the 'bucket of Fig. l, with one of the hinges shown partiallyv in longitudinal section.

Fig. 3 is a detail sectional view of the bearing structure incorporatedin the swiveled fairelead.

Fig. 4 is a side elevation of the bucket, but shown in its open position.

Figs. 5 and 6 are fragmentary plan views'of the bucket, showing the swiveled fair-lead in re'- spectively different angular positions therefor.

While the invention is susceptible of various modicatio-ns and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but

it is to be understood that Ido not thereby intend to limit the invention to the specific form disclosed, butintend to coverrall modifications and alternative constructions falling withinthe spirit and scope of the invention as expressed in the appended claims..

' Referring more particularly to the exemplary structure, the bucket shown comprises a bucket head Illand a hinge headII. Extending sides bye-side through the latter is a pair of hingepins I2,V journaled. within suitable bearings `I3-in the hinge head as indicated in Fig; 2. Pinned to the outer endsA of the hinge pins I2 are` upstanding arms I4a of a pair of opposed scoops or shells I4. Removable counterweights Ila are mounted on the hinge head to assure proper opening of thev bucket if desired. The buckethead I0 is of 'inverted box shape, being preferably comprised of plates weldedtogether to form side walls Illa, end'walls/ 10b, and a top wall Illc reenforced by gussets IUd. f To the'four corner portions of the lbucket head I0 are pivotally connected the usual lever arms I5, which are pivotallyconnected at their opposite or-lower ends to the respective outer corners of the scoops I4. y

As to the two lines for the bucket, the hoist line I6 is secured by-aclamp I1 carried by a clevis I8 on the bucket head Ill, while the closing line I9 is reeved over closing sheaves 20, V 2I attached, respectively, to the bucket head I IJ and theL hinge head II One end ofthe closing line lI9 is anchored to the bucket head I0 at 22, while the other or free end of the closing line is led 01T to a suitably located winchor the like (-not shown) for haulingin the same to pull the scoops I4 from the open position of Fig. 4 tothe closed position of Fig. l. 'I'he upper closing sheaves 20 are housed within the bucket head-II), being journaled between the side walls Illa of the latter, and the lower closing sheaves 2l are journaled in a support 23 fixed to the `top of the hinge head II.

To guide the so-called standing part of the closing line I9 asv it leaves the closing sheaves 20, 2|, and prevent kinking'or fouling of the same, a special swivel type fair-lead, designated generally by the numeral 24, is provided on the bucket head IIJ. In the construction illustrated, this fair-lead comprises an annular support 25 having a central opening or throat 26 (see Fig.`3) through which the closing line I9 passes. This throat is bordered by an annular depending sleeve 25a integral with the support; 25, and the latter also has at its perimeter a depending annular llange 25h. The sleeve 25a projects down into a central opening in a plate 28 bolted to the top plate IIJc of the bucket head which latter itself has a large central opening in it. A sleeve bearing 28a carried by the plate 28 journals the sleeve 25a and its attached support 25 for swiv eling motion about a vertical axis passing through the center of the throat 26. Antifriction thrust bearings 30, 3| are disposed above and below the plate 28, the upper bearing being encircled by the retaining flange 25h in support 25 and the lower bearing being held in place by a cover 25e removably fixed to the lower end of sleeve 25a.

Between upstanding side plates 29 xed to the support 25 is journaled a large diameter guide sheave, a complemental pair of such guide sheaves 21 being disposed in edge-to-edge relation on opposite sides of the throat 26 in the present instance and receiving the standing part of the closing line I9 between them, By using such large diameter guide sheaves, and swiveling them to remain in alignmentJ with the closing line irrespective of the angle at which the latter is led from the bucket, kinking r twisting of the closing line is effectually prevented.

To cause the swiveled fair-lead 24 to always assume a position in which the guide sheaves 21 are aligned with the closing line I9, a pair of guides in the form of elongated rollers 32 are utilized. These rollers are journaled between the end plates 29a fixed between the ends of the plates 29. The rollers are revoluble about axes at right angles to those of the guide sheaves and are disposed on opposite sides of the projected center line of the throat 26. The longitudinal slot thus formed between the rollers 32 permits the standing part of the closing line I9 to be swung laterally through a wide angle in leading loff the closing line to a desired point. Whenever the angle at which the closing line is led offv is changed, however, so that it would otherwise tend to assumeV an angular position with respect to the slot between the rollers 32, its engagement with the one of the latter rollers across which it is pulled swings the swiveled fair-lead around until ,the slotV between the rollers 32 is aligned with the closing line. Since such slot is aligned with the grooves in the peripheries of the guide sheavesr21, the latterare always maintained in substantially accurate alignment` with the portion'of the closing line leading from the bucket. As a result, theL closing line always enters and leaves the guide sheaves 21 without any twist ing or turning, so that there is no tendency for the same to kink, even though it be a heavy steel cable which is particularly subject to such diiliculty. i

Damage to the swiveled fair-lead 24 is prevented by an annular upstanding guard 33 weld ed to the top plate VIlle of the bucket head I6. This guardv extends in closely spaced and protective relation about the swiveling fair-lead struc ture so that both the swivel bearing and sheave bearings of the latter'are protected from damage during use of the bucket. This is particularly important in the event that the bucket falls over on its side, as frequently happens when it is dropped on a pile of material. Not only rare the parts of the-fair-lead mechanism 24 protected against breakage, but of perhaps even more importance, when the bucket is lying on its. 51de,

the fair-lead mechanism is free to swivel within the connes of the guard so that it is, even under suchadverse conditions, maintained in proper alignment with the closing line I9.

The general mode of operation of the bucket will be clear from the foregoing. By way of brief recapitulation, it may be noted that the bucket is customarily lowered onto a pile of material by slacking away the hoist line I6 with the closing line I9 also slacked off, so that the bucket is lowered while in the open position of Fig. 3. Thereafter, the closing line I9 is drawn up, thus closing the scoops I4 to claw up a load of material. Then the hoist line I6 is reeled in to transport the loaded bucket to a desired point of delivery. At the latter point, opening of the bucket is accomplished byslacking oil? the closing line I9 so that the scoops I4 are permitted to swing apart again to discharge their contents. At all times the fair-lead mechanism is siviveled by coaction of the rollers 32 with the line, in the manner heretofore described, so that the guide sheaves 21 are always accurately aligned with the closing line. Consequently, fouling and kinking of the latter are effectually prevented even though the angle at which the closing line passes from the bucket to the operator station may vary widely during use.

I claim as my invention:

l. In a clamshell bucket, the combination with a bucket head and a hinge head having closing sheaves attached thereto and movable toward each other as a closing line reeved over the sheaves is tensioned, of a fair-lead swiveled on the bucket head for movement about an axis aligned with the standing part of the closing line leaving said sheaves, said fair-lead including a guide slieave disposed with its edge aligned with said axis to receive the standing part of the closing line, and a guard structure on the bucket head protectively surrounding said fair-lead.

2. A two-line clamshell bucket comprising, in combination, a hinge head having an opposed pair of scoops pivotally connected thereto, a bucket head having means thereon for attachment to a hoisting line, a pair of closing line sheaves connected, respectively, to said bucket head and hinge head and having a closing line reeved thereon, a fair-lead for the closing line comprising a support having a throat therein and a pair of sheaves journaled on said support in edge-to# edge relation on opposite sides cf said throat to receive between them the closing line emerging through said throat from the closing sheaves, bearing means mounting said support for swiveling motion on said bucket head about a vertical axis passing through said throat, means for caus ing said support to swivel about said axis in a direction to bring said guide sheaves into alignn ment with the closing line irrespective of the angle at which the latter is led away from the bucket, said last-named means including an elonn gated pair of guide members mounted on said support above the guide sheaves and extending at right angles to the axes of the latter and disposed on opposite sides of the center line of said throat projected upward between said guide sheaves, and an annular upstanding guard on said bucket head surrounding said guide sheaves in protective spaced relation thereto.

ERIC H. LICHTENBERG. 

